Telegraph key



Dec. 20, 1966 Filed June 5, 1963 A- PFEIFFER TELEGRAPH KEY 2 Sheets-Sheet 1 FIG 3 wa i ' ANDREW INVENTOR.

PFEIFFER ATTORNEY A. PFEIFFER TELEGRAPH KEY Dec. 20, 1966 Filed June 5, 1963 2 Sheets-$heet 2 R E mm WP W P W E R D N A ATTORNEY United States Patent 3,293,363 TELEGRAPH KEY Andrew Pfeitfer, Box 450, RED. 1, Old Lyme, Conn. 06371 Filed June 5, 1963, Ser. No. 285,790 7 Claims. (Cl. 178108) The present invention relates generally to improvements in electric switches and it rel-ates in particular to an improved telegraph key.

In wire and radio telegraphy a manually operated key is employed to send the coded messages. These telegraph keys are of various constructions ranging from the classical vertically operated telegraph key to the automatic key which is employed with an electronic keying circuit of Well known operation which produces successively spaced dot signals upon closing of one set of terminals and successively spaced dash signals upon the closing of another set of terminals. Between these two extremes is the socalled side-swiper key wherein the blade is horizontally actuated to close the key and the semi-automatic key which is likewise horizontally actuated and provided with a mechanism which successively opens and closes a contact when swung in one direction to produce corresponding successive dots and effects an ordinary contact closure when swung in the opposite direction. While the present invention relates primarily to an automatic key the principle embodied therein may be employed in the classical key and side-swiper key as well. In the conventional telegraph keys the key arm or blade is generally resiliently urged to its neutral position by spring means which are frequently adjustable. As a consequence these keys possess many drawbacks and disadvantages. The fineness and range of adjustment is limited and the achievement of an optimum feel or key reaction is quite difiicult. Furthermore, the use of conventional telegraph keys at high speeds and for long periods of time is quite tiring. Conventional keys otherwise leave much to be desired.

It is, therefore, a principal object of the present invention to provide an improved electric switch,

Another object of the present invention is to provide an improved telegraph key.

Still another object of the present invention is to provide an improved telegraph key for use with automatic keying circuits.

A further object of the present invention is to provide an improved telegraph key which may be operated at high speeds with great ease and a minimum of effort.

Still a further object of the present invention is to provide a telegraph key of the above nature characterized by its simplicity, ruggedness, versatility and fineness as well as a high range of adjustability.

The above and other objects of the present invention will become apparent from a reading of the following description taken in conjunction with the accompanying drawing wherein:

FIGURE 1 is a top plan view, partially in section, of a telegraph key embodying the present invention;

FIGURE 2 is a rear elevational view thereof;

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 1;

FIGURE 4 is a sectional view taken along line 4-4 of FIGURE 1;

FIGURE 5 is a sectional view taken along line 55 of FIGURE 1;

FIGURE 6 is a sectional view taken along line 6-6 of FIGURE 1;

FIGURE 7 is a fragmentary plan View of the magnet structure of another embodiment of the present invention; and

FIGURE 8 is a side elevational View of the structure of FIGURE 7.

Patented Dec. 20, 1966 In a sense, the present invention contemplates the provision of an electric switch comprising a contact element, a swingable blade member movable between positions in and out of engagement with said contact element and means including a magnet resiliently urging said blade to a position out of engagement with said contact element.

According to a preferred form of the present invention, as applied to a telegraph key for use as such or with an automatic keying circuit, there is provided a base member on which a lever is pivotally mounted at a, point between its ends for swinging horizontally about a vertical axis. The lever include a rearwardly directed handledefining arm and a forwardly directed arm which carries a pair of contact elements. A pair of relatively stationary contact elements are adjustably mounted on the base member in registry with corresponding of the arm-mounted contact members, the lever being swingable to positions alternatively engaging said stationary contact elements and an intermediate neutral position out of engagement therewith. A first forwardly directed permanent magnet is mounted at the free end of the forwardly directed lever arm and a second stationary permanent magnet is longitudinally adjustably mounted on the base member. Opposite poles of the first and second magnets are in closely spaced confronting registry when the lever is in its neutral position and the magnets normally resiliently urge the lever to such neutral position by the magnetic pull therebetween. At least one and preferably both of the magnets have their confronting faces tapered to relatively sharp vertical leading edges.

Referring to the drawings, and particularly to FIG- URES l to 6 thereof which illustrate a preferred embodiment of the present invention, reference numeral 10 generally designates the improvide telegraph key which is of the double-throw automatic type, and includes a rectangular base member 11 advantageously formed of metal such as cast iron which delineates the electrical ground of the telegraph key. Any suitable binding post as 12 is mounted on base 11 adjacent its rear edge and is electrically connected to the base 11. Four curved foot pieces 13 formed of rubber or other suitable material are affixed to the underface of the base 11 adjacent the corner thereof to facilitate the firm positioning of the telegraph key.

Positioned atop base 11 and suitably affixed thereto is a longitudinally extending mounting block 14 formed of a rigid electrically insulating material, preferably a synthetic organic resin such as a polyacrylate, a phenol formaldehyde resin, a high impact polystyrene, a polyester or the like. Mounting block 14 includes a pair of transversely spaced longitudinally extending arms 16 having rectangular recesses or cutouts formed in the top faces thereof extending from the rear edges of the arms 16 to points intermediate their ends. A pair of legs 17 of slightly less height than arms 16 and formed integrally therewith project from the front inner faces of arms 16 toward each other the legs 16 having spaced confronting parallel vertical faces 18. The rear ends of arms 16 are connected by an integrally formed, transversely extending cross-piece 19 of the height of arms 16 at the center thereof, and cut out at the corners in alignment with the recesses in arms 16.

Nesting in each of the recesses formed in arms 16 and cross-piece :19 is a conductor and contact mounting bar 26 .of a configuration mating said recesses. The mounting bars 20 are formed of metal, for example brass, and are secured to arms 16 by screws 21 registering with bores in bars 20 and engaging aligned tapped bores formed in arms 16.

Bars 20 have transversely aligned tapped bores 22 formed therein adjacent their front ends, and a transversely horizontal slot 23 extends from each bore 22 to the front face of each block 20. A screw 24 registers a witha vertical bore in each of the bars 20 which bore intersects the slot 23, the lower section of the bore being tapped and engaged by the screw 24 to permit radial expansion and contraction of the transverse bores 22. Engaging each of the bores 22 and projecting inwardly of the bars 20' is a contact member-defining Allen head screw 26 carrying at its inner end a contact element 27 formed of a suitable contact material, such as silver or the like.

In order to facilitate the connection of the key to the corresponding terminals of a keying circuit, wire or phone tip receiving bores 28 are formed in the rear faces of the bars 20. Transversely extending tapped bores 29 are also formed in the bars 20 and communicate with the bores 28 and are engaged by suitable screws which permit the releasable locking of the conductors when disposed Within the bores 28 in electrical connection with the contact members 26 by way of the bars 20.

A metal plate 30 bridges the top of the block arms 17, engaging recesses in the top face there-of, and is secured thereto by screws 32. A first or lower bearing member is formed of metal and is aflixed to base 11 and includes a head 33 having a conical recess and a depending threaded shank which engages a correspondingly tapped vertical bore formed in base 11. A second or upper bearing member likewise formed of metal, comprises a threaded shank 36 engaging a correspondingly tapped opening in plate 30 and having a conical recess formed in the under face thereof, the upper and lower bearings being in vertical alignment. In order to facilitate the vertical adjustment of the upper bearing, a slot is formed in the top face of shank 36 and the upper bearing may be releasably locked in a preadjusted position by a knurled lock unit 37 engaging shank 36 directly above plate 30.

The telegraph key is provided with a swinging arm 38 including a longitudinally extending light metal bar 39 preferably formed of aluminum or the like. A vertical bearing pin 40 is afiixed to and passes through bar 39 adjacent its front end and terminates in conical tips engaging the upper and lower bearing recesses thereby to support arm 39 for swinging about a vertical axis in the absence of substantial friction. The bearing support of the arm 38 may be adjusted by means of adjustment of the upper bearing member 36 as earlier described. An easily manipulable knob 41 of any desired shape is affixed to the front end of the bar 39 forward of pivot pin 40.

A pair of opposite contact buttons or elements 35 is mounted on and electrically connected to bar 39, the contact elements being in aligned confronting relationship with stationary contact elements 27 and being swingable with the arm 38 into alternative engagement therewith or into an intermediate neutral position out of engagement with both contact elements 27.

(Formed in the rear end of bar 39 is a longitudinally extending well 42 which slidably telescopically engages a high strength bar magnet 43 which is advantageously of the Alnico or ceramic type, having opposite poles at opposite ends thereof. Magnet 43 projects rearwardly out of well 42 in bar 43 and is releasably locked in an adjusted position by means of a set screw 44 engaging a tapped transverse bore extending vertically from the upper face of bar 39 and communicating with well 42. A second bar magnet 46 of high strength likewise formed of Alnico or a ceramic material has opposite poles at opposite ends and slidably registers with and extends through a longitudinal bore medially formed in cross-piece '19 at the level of and coaxial with the first magnet 43. It should be noted that when bar 39 is in its neutral position, intermediate block arms 16, magnets 43 and 46 are in axial alignment. Magnet 46 is provided with a knob 47 at its rear end to facilitate the longitudinal adjustment thereof, and the magnet 46 is releasably locked in a preadjusted position by means of a set screw 48 engaging a tapped bore extending vertically from the upper face of cross-piece 19 and communicating with the longitudinal bore engaging magnet 46. The confronting ends of magnets 43 and 46 are opposite poles so that the key arm 38 is magnetically resiliently urged to and retained in its intermediate or neutral position. It should be noted that either or both of the magnets 43 and 46 may be in the form of threaded rods and may engage correspondingly tapped bores in the respective support members to facilitate the fine longitudinal adjustment thereof.

In employing telegraph key 10 described above in automatic keying the conductor bars 20' are connected to the opposite dot and dash terminals of an automatic keying circuit, and arm 38 is connected to the ground terminal thereof through binding post 12. By swinging key arm 38 in one direction or the other by means of knob 41 in accordance with the usual practice the corresponding contact element 27 is engaged by the contact element 35 to energize the respective section of the keying circuit in the known manner. Upon release of the knob 41 the arm 38 is returned to its neutral position by reason of the attraction between the opposite poles of magnets 43 and 46. The sensitivity, response and feel of the telegraph key may be finely adjusted within a wide range by adjusting the positions of the cont-act elements 27 and 35 and the relative positions of magnets 43 and 46. The smaller the spacing between magnets 43 and 46 the greater the force returning the arm 38 to and retaining it in its neutral position and stiffer the feel 'of the key. It

should be noted that by reason of the absence of mechanical return mechanisms the energy losses attendant the use of the present improved telegraph key is minimized, with a consequent increase in efliciency and a reduction in fatigue.

In FIGURES 7 and 8 of the drawing there is illustrated another embodiment of the present device differing from that first described only in the configuration of the confronting portions of the magnets. Specifically, the first and second magnets 49 and 50- correspond to the magnets 43 and 46 respectively, and are similarly associated with the rest of the telegraph key. The confronting faces of the magnets 49 and 50 are tapered to vertical knife edges 51 which may be blunt, as illustrated, or sharp. When key arm 5-2 is in its intermediate neutral position the knife edges 51 are in longitudinal alignment. The key arm return force, employing the magnets 49 and 50 is greatly increased, particularly adjacent the intermediate neutral position of the arm 52 by reason of the great concentration of the magnetic lines of force at knife edges 51.

While there have been described and illustrated preferred embodiments of the present invention, it is apparent that numerous alterations, omissions and additions may be made without departing from the spirit thereof.

What is claimed is:

1. A telegraph key comprising a base member, a pair of spaced contact elements mounted on said base member, an arm swingably mounted on said base member and rockable between positions alternately engaging said contact elements and an intermediate neutral position out of engagement with said contact elements, a manipulating handle mounted on said arm for movement thereof, a first permanent magnet on said arm at the end remote from said manipulating handle and movable therewith, and a second relatively stationary permanent magnet mounted on said base and closely spaced to the path of said first magnet, said first and second magnets having opposite poles in confronting registry when said arm is in said intermediate neutral position.

2. The telegraph key of claim 1, including means for adjusting the relative spacing between said first and second magnets.

3. The telegraph key of claim 1, wherein at least one of said magnets has a tapered end face confronting the other of said magnets.

4. A telegraph key comprising a base member, a lever pivotally mounted at a point between the ends thereof to said base member and rockable about a vertical axis, said lever including a forwardly directed first arm and a rearwardly directed handle defining second arm, a pair of first and second relatively stationary contact elements mounted on said base member along opposite sides of said first arm, said first arm being swingable horizontally into alternate engagement with said contact elements and into an intermediate neutral position out of engagement therewith, a first permanent magnet mounted on said first arm adjacent the free end thereof and having a rearwardly directed first magnetic pole, and a second relatively stationary permanent magnet mounted on said base member and having a forwardly directed second magnetic pole opposite said first pole and in closely spaced registry with said first pole when said arm is in said intermediate neutral position.

5. The telegraph key of claim 4, including means for References Cited by the Examiner UNITED STATES PATENTS 2,724,794 11/ 1955 Van Bennekom 3 l7171 3,098,898 7/1963 Jakosky et al 178-108 3,160,705 12/1964 Stout 178-108 NEIL C. READ, Primary Examiner.

THOMAS A. ROBINSON, Examiner. 

1. A TELEGRAPH KEY COMPRISING A BASE MEMBER, A PAIR OF SPACED CONTACT ELEMENTS MOUNTED ON SAID BASE MEMBER. AN ARM SWINGABLY MOUNTED ON SAID BASE MEMBER AND ROCKABLE BETWEEN POSITIONS ALTERNATELY ENGAGING SAID CONTACT ELEMENTS AND AN INTERMEDIATE NEUTRAL POSITION OUT OF ENGAGEMENT WITH SAID CONTACT ELEMENTS, A MANIPULATING HANDLE MOUNTED ON SAID ARM FOR MOVEMENT THEREOF, A FIRST PERMANENT MAGNET ON SAID ARM AT THE END REMOTE FROM SAID MANIPULATING HANDLE AND MOVABLE THEREWITH, AND A SECOND RELATIVELY STATIONARY PERMANENT MAGNET MOUNTED ON SAID BASE AND CLOSELY SPACED TO THE PATH OF SAID FIRST MAGNET, SAID FIRST AND SECOND MAGNETS HAVING OPPOSITE POLES IN CONFRONTING REGISTRY WHEN SAID ARM IS IN SAID INTERMEDIATE NEUTRAL POSITION. 